Wire drawing machine



Oct. 9, 1934. w, RQHN 1,976,247

WIRE kDRAWING MACHINE Filled NOV. 14. 1951 fige Patented ct. 9, .1934

UNITED STATES 1,976,247 WIRE DRAWING MACHINE Wilhelm Rohn,Hanau-on-the-Main,

K Germany Application November 14 1931, Serial No. 575,104

In Germany November 15, 1930 3 Claims.

This invention relates to improvements in wire drawing machines.

The invention is illustrated in the annexed drawing of which Fig. 1 is adiagrammatic lone gitudinal section showing the general arrange-l mentof the elements of the machine. Fig. 2 is a cross-sectional View on anenlarged scale. Figs. 3 and 4 show a front view and a side viewrespectively of one of the motors combined with an intermediate geartrain.

In the case of machines of older construction for drawing wire in anumber of operations all the drawing discs are driven from a commonshaft, that is to say with rigid ratios as regards the relative speedsof rotation. It is well known that in connection with such machines anun-` desirable wear of vthe drawing discs takes place as it is necessaryto permit of a continuous backward slipping of the wire relatively tothe draw- 20 ing discs as it is practically impossible to impart exactlythe theoretical correct ratio to the reductions in cross sections of thewire in the separate drawing dies and to the peripheral speeds of theseparate drawing discs, and to the actual surface of the winding reel atthe succeeding times. In order to overcome this objection it has beenproposed to drive each separate drawing disc by means of a separatemotor and to provide the motors with such regulating devices thatslipping of the wire relatively to the drawing discs is obviated.

Such devices have proved entirely satisfactory in practice, but theireconomical result was, however, very unsatisfactory as in theseconstructions it was necessary to provide a separate gear train betweeneach separate motor and the drawing disc driven thereby. It is, however,clear that it is considerably more inconvenient and expensive forexample in a drawing machine in which a ten fold reduction is to beproduced to have ten separate gear trains between the ten motors and theten drawing discs, than to have a single motor and a combined gear trainby which all the drawing discs are driven.

The diculty above referred to can be overcome and a particularly simpleand inexpensive construction of multi-wire drawing machines is obtainedif the use of gear trains between the driving element and the drawingdiscs are omitted and the drawing discs are connected directly t'o thefree shafts of the driving elements. This construction disregarding theregulation of the Y separate driving elements, has considerableadvantages as will be described hereinafter. In order not to arrive atuneconomical slowly rotating types of motors -it is preferable to makethe drawing discs only about twenty to forty times the diameter of thewire when mounting the drawing discs on the shafts of the usual electricmotors. Thorough researches have shown that the quality of the drawnwire is in no way influenced deleteriously in this manner. If, forexample, it is desired to draw 1 mm. wire at a speed of 120 m. perminute, 2 m. per second, there may be used for this purpose a drawingdisc having a diameter of 40 mm. which is mounted directly on the shaftof a motor making 1,000 revolutions per minute. A

According to the present invention it is also possible to use drawingdiscs of substantially larger diameter and in spite of this to retainthe simple construction of the drawing machine from units which are eachseparately removable from a base plate if the driving discs are mountedon -the'shafts of the driving elements which in the 75 known mannerconsist of a motor built together with a simple gear.

For the construction by way of example of a ten fold wire drawingmachine wherein the Wire to be drawn is to be reduced in cross sectionby 20% on each separate drawing disc there are the followingpossibilities of construction. The complete reduction in cross sectionof the wire which'is Supplied to the rst drawing disc to the wirepassing from the last drawing disc amounts to about 1:6 so that thedelivery speed amounts to about six times the feeding speed. It is thenpossible to make all the drawing discs of the same diameter and, forexample, drive the rst drawing disc by a motor with 500 revolutions perminute and the last drawing disc by a motor making 3,000 revolutions perminute. Or all the motors may have the same speed and the last drawingdiscs are made six times the diameter of the first drawing discs.Finally a portion of the increase in speed of the wire may be obtainedby increasing the speed and a portion by increasing the diameter of thedrawing discs. 'Ihe rst method of operation is used with particularadvantage when the same operation is always to be carried out in thedrawing machine. It becomes still more favourable when in the drawingmachine, for example, as a rule wire is to be drawn from 5 mm. to 1 mm.and when in a particular case for example it is desired to obtain wirehaving 105 a diameter of 2 mm. In this case the motors with the drawingdiscs which are required for drawing Afrom 2 to 1 mm. are removed andput .m another base-plate and are used for the separate drawing ofanother quantity of material, from 2 to 1 mm. 110' 1 mm. to separate thelast veAmotors and assemble them so as to form a separate drawingmachine. If then the drawing discs originally tted to these motors arereplaced by suitably smaller drawing discs then it is possible by meanslof these iive separated elements also to draw wire from 2 to 1 mm. Thetwo groups of operating elements are then to a certain extent arrangedin parallel. For other purposes of use it will be 'understood that asuitable sub-division of the original machine can be effected and theseparate elements suitably assembled.

The third method of operation is used when it is desired to effect avery considerable reduction in diameter in the machine. It is then inpractice extremely diflicult in many cases to reduce the speeds ofrotation ofthe driving motors in a suitable manner when the drawingdiscs are all of the same diameter as it would be necessary for theilrst motor to have an abnormally low speed or an abnormally high speedof rotationfor the last motor. In such cases it is advisable besideseffecting a gradation by means of the speed of rotation of the motorsalso to effect an additional gradation by making the drawing discs ofdinerent diameters.

By means of the multi-wire drawing machines above described thefollowing advantages are also obtained.

It is only necessary to provide solely separate motors each of which ifdesired is built together with a simple gearing so as to form a. unitand bolted side by side for example, on a U-shaped iron. Such motors canbe obtained at anytime from stock or are obtainable very quickly. lerequirement of special parts is solely in res t of simple andinexpensive drawing discs. It is clear that electric motors as standardarticles can be obtained quicker and more cheaply than wire drawing-machines with individually constructed gear trains. Wire drawingmachines composed of separate motors have at the same time also theadvantage of particular adaptability. If, for example, it is necessaryon one occasion to produce a small quantity of thin wires then forexample it is possible to .construct from 120 separate motors withdrawing discs applied thereto 10 twelve-fold drawing machines in that 12separate motors are bolted side by side, for example, on a U-shaped ironplate forming a bed. If at another time it is necessary to produce alarger weight of thicker wires. the same 120 separate electric motorsare, for exarnple, assembled so as to form 15 eight-fold drawingmachines or 20 six-fold drawing machines. i

Although the costs of installing a drawing ma'.- chine according to thepresent invention are not higher than those for the usual drawingmachines the driving members vin the case of a machine which would haveto be scrapped prematurely have a considerably higher value than thoseof the known drawing machines. In the known arrangements the gear trainswhich are mounted in the machines separately from the driving memberscan only be used usefullyin the rarest of cases. As, however, separatelyconstructed gear trains in the known arrangement constitute the mainportion of the costs of installation of the machine then when themachine is no more in use- 'a considerable portion of the costs expendedbecome practically Valueless.

It is known to arrange separate elements of a wire drawing machinewithin a common framework. ;In the known drawing machine it was,however, not possible to simply and easily exchange the' separateelements mounted on the base plate as gear trains and drawing discs foreach separate element were mounted separately on the bed.

Figure 1 of the accompanying drawing shows diagrammatically inlongitudinal section the arrangement of the separate drawing machineelements in accordancewith the applicationmounted on a baseplate, whilstFigure 2 shows a cross section of a drawing machine. On a U-shaped ironA are tted motors' M1, Mz and so forth. On the shafts B of the motorsare tted the drawing discs C. The drawing dies D are supported on aseparate U-iron E. From Figure 1 it will be clearly seen that a.suitable group of motors (indicated in the drawing by dotted lines) canbe separated and assembled to form'a separate drawing machine. In Figure1 there are indicated on the separate motors the number of revolutionswhich these motors may, for example, have.

Figures 3 and 4 of the accompanying drawing show a driving elementconsisting of a motor combined with an intermediate gear train. Adriving ring is mounted upon the free shaft of the gearing.

The two `-bearing shields a and b of the electric motor c shown inFigure '4 are each provided with an extension, each of which has abearing d and e for the shaft f. The end of the shaft of the electricmotor opposite to the operative side carries a pinion g gearing with atoothed wheel h on the shaft f whilst at the opposite end of the shaft fthere is fitted the drawing disc.

As for reasons of economy in space it is particularly important toarrange the drawing dies as .closely behind one' another as possible thegearings'referred to are arranged above or underneath the electricmotors so that the entire extent in width of the driving element to benxed to the bed is not larger than that of the electric 'motor itself.

In order to compensate for slight differences which must occur in thespeeds of rotation of the separate motors by reason of the fact that thediameter of the ldrawing dies can never be accurately met in practice tocorrespond to the theoretical stepping, there may be used variousmethods, which are partly known, for example the construction of theseparate motors as soft compounded compound motors or the use of shuntwound motors or compound motors having resistances, in series to thearmatures. (S0ft compounded motor in this connection means acumulatively wound motor, i. e. a motor of which the speed decreasessubstantially as the load increases.) It may also be mentioned that thewaste of a portion of the electrical'energy in these resistances doesnot represent any increased consumption of current relatively to thepreviously known constructions of multiple drawing machines as by theomission of the intermediatev gearings trains and the slip between thewire and the drawing discs there are also eliminated the unavoidablelosses of energy by friction and within these intermediate gearingtrains.

I claim:-

1. A multiple wire drawing machine composed of a simple base plate, anumber of separate units screwed on the said baseplate and being readilyremovable as units, each unit consisting of an electric motor as drivingelement and -a drawing drum fitted to the shaft of said unit.

2. A multiple wire drawing machine composed y of a simple base plate, anumber of separate units screwed on the said baseplate and being readilyremovable as units, each unit consisting of an

